On the eighth day of the "12 Days of Retool" series, the focus is on creating a simple 8-bit arcade app using Retool, leveraging features such as iframes, temporary state variables, and list view components. The project involves embedding eight famous games, like Super Mario Bros and Pac-Man, using the Retool IFrame component, which allows HTML pages to be embedded within apps and requires specific permissions for emulators to function. Temporary state variables store game data, while the List View component dynamically renders this data, eliminating the need for repetitive code. The app enables users to switch between games using a Play button, which modifies the IFrame URL upon each click, offering a streamlined approach to displaying multiple games within a single interface. The post encourages further exploration of the Retool blog for additional holiday hacks in the ongoing series.